<template>
  <div class="article-container">
    <!-- 导航栏 -->
    <van-nav-bar class="page-nav-bar" left-arrow title="黑马头条"></van-nav-bar>
    <!-- /导航栏 -->

    <div class="main-wrap">
      <!-- 加载中 -->
      <div class="loading-wrap" v-if="loading">
        <van-loading color="#3296fa" vertical>加载中</van-loading>
      </div>
      <!-- /加载中 -->

      <!-- 加载完成-文章详情 -->
      <div class="article-detail markdown-body" v-else-if="articalList.title">
        <!-- 文章标题 -->
        <h1 class="article-title">{{ articalList.title }}</h1>
        <!-- /文章标题 -->

        <!-- 用户信息 -->
        <van-cell class="user-info" center :border="false">
          <van-image
            class="avatar"
            slot="icon"
            round
            fit="cover"
            :src="articalList.aut_photo"
          />
          <div slot="title" class="user-name">{{ articalList.aut_name }}</div>
          <div slot="label" class="publish-date">
            {{ articalList.pubdate | relativeTime }}
          </div>
          <!-- <van-button
            class="follow-btn"
            round
            size="small"
            v-if="articalList.is_followed"
            @click="onFollow"
            :loading="followLoading"
            >已关注</van-button
          >
          <van-button
            class="follow-btn"
            type="info"
            color="#3296fa"
            round
            size="small"
            icon="plus"
            v-else
            @click="onFollow"
            :loading="followLoading"
            >关注</van-button
          > -->
          <!-- 这个$event就是子组件事件参数，也就是子组件传过来的值 -->
          <user-follow
            :is_followed="articalList.is_followed"
            class="follow-btn"
            :userId="articalList.aut_id"
            @updateView="articalList.is_followed = $event"
          ></user-follow>
        </van-cell>
        <!-- /用户信息 -->

        <!-- 文章内容 -->
        <div
          class="article-content"
          v-html="articalList.content"
          ref="articalList.content"
        ></div>
        <van-divider>正文结束</van-divider>
        <div class="article-bottom">
          <van-button class="comment-btn" type="default" round size="small"
            >写评论</van-button
          >
          <van-icon name="comment-o" info="123" color="#777" />
          <!-- <van-icon color="#777" name="star-o" /> -->
          <collect-artical
            :isCollected="articalList.is_collected"
            :userId="articalList.art_id"
            @upDateCollect="articalList.is_collected = $event"
          ></collect-artical>
          <!-- <van-icon color="#777" name="good-job-o" /> -->
          <like-artical
            :attitude="articalList.attitude"
            :userId="articalList.art_id"
            @updateLike="articalList.attitude = $event"
          ></like-artical>
          <van-icon name="share" color="#777777"></van-icon>
        </div>
      </div>
      <!-- /加载完成-文章详情 -->

      <!-- 加载失败：404 -->
      <div class="error-wrap" v-else-if="errStatus === 404">
        <van-icon name="failure" />
        <p class="text">该资源不存在或已删除！</p>
      </div>
      <!-- /加载失败：404 -->

      <!-- 加载失败：其它未知错误（例如网络原因或服务端异常） -->
      <div class="error-wrap" v-else>
        <van-icon name="failure" />
        <p class="text">内容加载失败！</p>
        <van-button class="retry-btn">点击重试</van-button>
      </div>
      <!-- /加载失败：其它未知错误（例如网络原因或服务端异常） -->
    </div>

    <!-- 底部区域 -->
    <!-- 由于文章的底部区域是在发起文章详情的请求之前就加载出来了，因此在<collect-artical
      :isCollected="articalList.is_collected"
    ></collect-artical
    >这行代码里面的articalList.is_collecte是在数据请求回来之后才加载出来的，因此使用的时候会报错，可以考虑将底部的区域放到文章详情数据请求回来之
    后再来渲染 -->
    <!-- <div class="article-bottom">
      <van-button class="comment-btn" type="default" round size="small"
        >写评论</van-button
      >
      <van-icon name="comment-o" info="123" color="#777" />
      <van-icon color="#777" name="star-o" />
      <collect-artical
        :isCollected="articalList.is_collected"
      ></collect-artical>
      <van-icon color="#777" name="good-job-o" />
      <van-icon name="share" color="#777777"></van-icon>
    </div> -->
    <!-- /底部区域 -->
  </div>
</template>

<script>
import { getArticalDetails, addFollow, deleteFollow } from '@/api/artical.js';
import { ImagePreview } from 'vant';
import UserFollow from '@/components/user_follow';
import CollectArtical from '@/components/CollectArtical';
import LikeArtical from '@/components/likeArtical';
export default {
  components: {
    UserFollow,
    CollectArtical,
    LikeArtical,
  },
  props: {
    articalId: {
      type: [String, Number, Object],
      required: true,
    },
  },
  data() {
    return {
      // 文章数据
      articalList: {},
      // 控制加载中的显示和隐藏
      loading: true,
      // 控制错误的原因的显示
      errStatus: 0,
      // 控制点击按钮的加载装态，默认为false,不显示
      followLoading: false,
    };
  },
  created() {
    this.loadArticalDetails();
  },
  methods: {
    async loadArticalDetails() {
      try {
        const { data } = await getArticalDetails(this.articalId);
        // console.log(data);

        // 测试用的报错代码
        // if (Math.random() > 0.2) {
        //   JSON.parse('ahsldkjfhlakd');
        // }
        this.articalList = data.data;
        // console.log(this.articalList);
        // 文章图片放在文章里面，也就是说图片的获取是要请求完成之后才可以的
        // this.$nextTick(() => {
        //   // this.previewImg();
        // });
        setTimeout(() => {
          this.previewImg();
        }, 0);
      } catch (err) {
        if (err.response && err.response.status === 404) {
          this.errStatus = 404;
        }
        this.$toast('获取文章详情数据失败！');
      }
      // 不管是否成功的获取文章详情的数据，都要将loading关闭
      this.loading = false;
    },
    // 预览图片
    previewImg() {
      // const images = this.$refs['articalList.content'];
      // 这个时候不能立即拿到articalList.content的vue实例的节点信息，因为数据驱动视图的更新不是立即的
      // 这行代码的意思是获取元素节点
      const articalNode = this.$refs['articalList.content'];
      // 获取所有的图片节点
      const imgs = articalNode.querySelectorAll('img');
      // console.log(images);
      // 遍历这个图片节点数组
      const images = [];
      imgs.forEach((img, index) => {
        images.push(img.src);
        img.onclick = () => {
          // 图片预览组件
          ImagePreview({
            images,
            // 指定初始图片位置，从零开始，点击哪张图片就从哪张开始
            startPosition: index,
          });
        };
      });
    },
    // 关注事件
    async onFollow() {
      // 请求开始，将loading展示出来
      this.followLoading = true;
      try {
        if (this.articalList.is_followed) {
          // 已关注用户,则点击取消关注
          await deleteFollow(this.articalList.aut_id);
          // this.articalList.is_followed = false;
        } else {
          await addFollow(this.articalList.aut_id);
          // this.articalList.is_followed = true;
        }
      } catch (err) {
        let message = '操作失败，请点击重试！';
        if (err.response && err.response.status === 400) {
          message = '不能关注用户本身！';
        }
        this.$toast(message);
      }
      this.articalList.is_followed = !this.articalList.is_followed;
      // 请求结束，将loading隐藏起来
      this.followLoading = false;
    },
  },
};
</script>

<style lang="less" scoped>
@import './github-markdown.css';
.article-container {
  .main-wrap {
    position: fixed;
    left: 0;
    right: 0;
    top: 92px;
    bottom: 88px;
    overflow-y: scroll;
    background-color: #fff;
  }
  .article-detail {
    .article-title {
      font-size: 40px;
      padding: 50px 32px;
      margin: 0;
      color: #3a3a3a;
    }

    .user-info {
      padding: 0 32px;
      .avatar {
        width: 70px;
        height: 70px;
        margin-right: 17px;
      }
      .van-cell__label {
        margin-top: 0;
      }
      .user-name {
        font-size: 24px;
        color: #3a3a3a;
      }
      .publish-date {
        font-size: 23px;
        color: #b7b7b7;
      }
      .follow-btn {
        width: 170px;
        height: 58px;
      }
    }

    .article-content {
      padding: 55px 32px;
      /deep/ p {
        text-align: justify;
      }
    }
  }

  .loading-wrap {
    padding: 200px 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: #fff;
  }

  .error-wrap {
    padding: 200px 32px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background-color: #fff;
    .van-icon {
      font-size: 122px;
      color: #b4b4b4;
    }
    .text {
      font-size: 30px;
      color: #666666;
      margin: 33px 0 46px;
    }
    .retry-btn {
      width: 280px;
      height: 70px;
      line-height: 70px;
      border: 1px solid #c3c3c3;
      font-size: 30px;
      color: #666666;
    }
  }

  .article-bottom {
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    display: flex;
    justify-content: space-around;
    align-items: center;
    box-sizing: border-box;
    height: 88px;
    border-top: 1px solid #d8d8d8;
    background-color: #fff;
    .comment-btn {
      width: 282px;
      height: 46px;
      border: 2px solid #eeeeee;
      font-size: 30px;
      line-height: 46px;
      color: #a7a7a7;
    }
    .van-icon {
      font-size: 40px;
      .van-info {
        font-size: 16px;
        background-color: #e22829;
      }
    }
  }
}
</style>
